Reptiles, which obtain body heat from their surroundings, are more prevalent on the sunny prairies than the higher elevations of the Crown of the Continent. Rattlesnakes and other species hunt mice and other small animals, some with a hemotoxic venom delivered via a lightning fast bite. Their rattling tails warn off many predators. Garter snakes feed on earthworms and insects, squirting a foul-smelling fluid to ward off threats from larger animals. Turtles eat vegetation near low elevation lakes and retreat to the security of their shells when troubled.
Reptiles are one of the oldest class of animals on the Earth.